
<script src="https://cdn.staticfile.org/jquery/3.4.1/jquery.min.js"></script>
<div></div>

<script>

    let colors =[
    "black" , "white", "red" ,
    "orange" , "yellow", "lime",
    "blue", "cyan" , "purple"
    ];
    
    let i=Math.floor(Math.random()*9); 
    
    $("body")
    
        .css("background-color",colors[i]); 

</script>